U.S. Pat. No. 3,860,316 shows a connector assembly comprising a connector plug and a connector receptacle which has a plug receiving opening extending inwardly from its mating face. The plug has contact terminals therein having contact portions on one of the plug sidewalls adjacent to the leading or mating end of the plug and the receptacle has receptacle contacts comprising cantilever spring arms which are engaged by the plug contacts. When the parts are mated, the plug and receptacle are latched to each other by means of a latch arm provided on the plug sidewall which is opposite to the sidewall on which the contacts are provided. A complementary receptacle latch is provided on the opening sidewall of the receptacle. The latching shoulders of the plug and the receptacle are therefore within the plug receiving opening of the receptacle and the overall dimensions of the connector assembly can be quite small as a result. Furthermore, the latching mechanism, being inside the plug receiving opening of the receptacle, is protected from damage. Connector assemblies of the type shown in U.S. Pat. No. 3,860,316 are widely used in telephone equipment and related equipment. Connector assemblies of this type are produced with four to eight contact terminals but are not made in larger sizes.
lt would be desirable to produce connector assemblies of the type described above which would be suitable for use with computers and computer-related equipment, however, it would be necessary to provide a range of sizes for varying numbers of conductors. The latching system used with connector assemblies of the type described in U.S. Pat. No. 3,860,316 would not be satisfactory for assemblies designed to connect more than about eight conductors, that is, they would not be satisfactory if the plug and receptacle were significantly wider than the plugs and receptacle presently being used. The present invention is thus directed to the achievement of an improved latching system which does permit the design of assemblies capable of accomodating increased numbers of conductors.
An electrical plug in accordance with the invention comprises an insulating housing having a leading end and a conductor-receiving end which faces oppositely with respect to the leading end, oppositely facing first and second sidewalls and oppositely facing endwalls extending from the leading end to the conductor-receiving end. A conductor-receiving opening extends inwardly from the conductor receiving end towards the leading end; and contact-receiving cavities having plug terminals therein are provided in the housing at the leading end for contacting conductors extending into the conductor-receiving opening. The plug connector is characterized in that each of the endwalls has a latch arm associated therewith, each latch arm having a fixed end and a free end, the fixed end being integral with the endwall adjacent to the leading end of the housing and the free end being proximate to the conductor-receiving end of the housing. Each latch arm extends divergently from its associated endwall from the fixed end to the free end. Each latch arm has a single rearwardly facing latching shoulder thereon intermediate its ends and has a handle portion extending from the latching shoulder to its free end. Each latch arm has an ear on its free end extending laterally towards the associated endwall, each ear being offset relative to its associated latch arm and lying in a plane which is parallel to, and spaced from one of the sidewalls, each ear substantially closing the gap between the free end of the latch arm and the associated endwall of the housing.
In accordance with further embodiments, the latching shoulders are in a medial plane which is parallel to, and between, the housing sidewalls and each latch arm has a single handle portion which is proximate the housing sidewall. Each latch arm has a forward portion which extends from the shoulder to the fixed end, the forward portion having a thickness, as measured normally of the planes of the housing sidewalls, which is less than the thickness of the housing, as measured between the housing sidewalls, and is at least one-half the thickness of the housing, the handle portion of each latch arm having a thickness which is less than the thickness of the forward portion by an amount equal to the thickness of the shoulder.
ln accordance with a further embodiment, a receptacle is provided for a connector plug as described above, the receptacle comprising a receptacle housing having a mating face and having a plug-receiving opening extending into the receptacle housing from the mating face, the plug-receiving opening having opposed first and second opening sidewalls and opposed opening endwalls, the plug-receiving opening being dimensioned to receive the plug, leading end first, with the first and second plug sidewalls opposed to the first and second opening sidewalls respectively. The electrical connector assembly is characterized in that the opposed opening endwalls have aligned receptacle shoulders thereon facing inwardly of the plug-receiving opening, the plug receiving opening having an intermediate width portion which is of an intermediate width, as measured between the opening endwalls, at the mating face in the vicinity of the receptacle shoulders, the plug receiving opening having a reduced width portion which is of a reduced width in the zone between the receptacle shoulders and the second opening sidewall, and the plug-receiving opening having an enlarged width portion which is of an enlarged width in the zone between the receptacle shoulders and the first opening sidewall, the opening being symmetrical about a medial plane extending normally of the opening sidewalls. The plug shoulders are engageable with the receptacle shoulders upon insertion of the plug into the plug-receiving opening, the handle portions being of reduced thickness, as measured normally of the plug housing sidewalls and being offset from the shoulders towards the second plug housing sidewall; parts of the handle portions, which are adjacent to the shoulders, being received in the enlarged width portion of the plug-receiving opening, the free ends of the latch arms being external to the plug-receiving opening to permit flexure of the latch arms towards the plug endwalls, disengagement of the plug shoulders from the receptacle shoulders, and removal of the plug from the receptacle.